Seat or cushion of combined springs and resilient pad construction



SEAT OR CUSHION OMBINED SPRINGS AND RESILIENT PAD CONSTRUCTION Filed March '7, 1960 Fb. 25,1964 s M TERR'Y ETAL 3,122,360

IN VENTOR Smm/E1. iV). FSE/ey' JOHN MEYEA ATTORNEY Unted States Patent C) 3,122,366 SEAT GR CUSHl-SN F CQMBKNED SPRlNGS AND PrlISlLlENT PAD CN-iTRUCTiN Samuel M. Terry, Ann Arbor, and .lohn S. Meyers, Allen Park, lvl'icli., assignors to Stubnitz Greene Corporation,

Adrian, l't/lich., a corporation of Michigan Filed Mar. 7, 196i), Ser. No. 13,002 3 Claims. (Cl. 267-84) The present invention relates to improvements in spring wire coil assemblies and method of making the same, for the seats and backs of vehicles, furniture, and the like, as well as general purpose resilient supporting surfaces such as mattresses, cushions, and the like. More specifically, the invention is concerned with the provision of a relatively thin, highly flexible and resilient spring wire coil assembly in which spring wire coils are associated with a slab of resilient foam material, the slab functioning to locate and support one end of the coils as well as to insulate the coils from the load supporting surface of the slab.

lt has been proposed, as disclosed in United States Patent No. 2,874,389, to embed opposite ends of spring coils in spaced slabs of polyurethane foam to provide a reversible inner spring foam mattress. As described in the aforesaid patent, polyurethane foam adheres strongly to the metallic surface of the spring coils. Polyurethane foam also has a chemical reaction with fibrous woven fabric to improve the structural properties of the fabric as disclosed in pending application Serial No. 672,278, filed July 16, 1957.

ln carrying out the present invention it is proposed to combine the slab, woven insulator and spring coils into a unitary structure. ln practice, the assembly takes the form of a slab of polyurethane foam which, in the mold, reacts against and through an openwork fabric and about one end of the spring wire coils to bond the fabric and coils into the body of the slab of foam material. The chemical reaction of the foam with the fabric improves its structural properties and assures the support of the coils against penetration into the body of the foam slab under conditions of use experienced in vehicle seats and backs. The ends of the coils opposite those attached to the foam slab are preferably attached to an inexpensive base which may be either relatively flexible or relatively rigid, depending upon the nature of support that is required for the superstructure.

In vehicle seating, it is proposed to use closely woven lO oz. burlap for the base for the spring wire coils, the coils being attached to the burlap base by a suitable adhesive. Preferably, the coils are attached to the burlap base by applying a layer of polyurethane foam to a surface of the burlap thenpositioning the ends of the coils agahist the burlap, embracing the ends of the coils in the foam and curing the foam. Aside from the firm bonding of the ends of the coils to the closely woven burlap, the polyurethane foam will penetrate the interstices of the burlap to improve the structural characteristics of the same. Thus treated, the burlap base may rest directly upon a subbase of spaced resilient spring elements of the vehicle seating structure. ln place of the closely woven burlap, the ends of the coils opposite the ends attached to the foam slab, may be attached to a base of paper, cardboard, iberboard, wood, plywood, sheet metal, or the like.

ln carrying out the method of manufacture of the present invention, the spring Wire coils are supported upon a suitable fixture to uniformly space and support, the same. While supported upon the fixture, the open-mesh fabric is imposed upon the exposed ends of the coils to confine the coils between the xture and the fabric. This assembly is then inverted and suspended in the HLSW Paten-ted Feb. 25, 19de.-

mold for the foam slab, the fabric being spaced above the bottom of the mold ay distance approximating the thickness of the cured slab. As the chemical reaction takes place in the mold, the foam is leveled and distributed by the openwork fabric with a portion of the foam passing through the fabric and embracing the ends of the coils. Following a precure in the mold the foam slab, openwork fabric insulator and spring Wire coil assembly is removed from the mold. The base may thereafter be applied to the ends of the coils opposite the foam slab either after nal cure or directly after the procure.

Thus, an object of the invention is to provide improvements in components used in seating structure and methods of making the same in which a flexible slab of cellular reaction material has integrally associated therewith an insulator, a plurality of spring wire coils and a base structure.

Another object is to provide an improved spring wire coil assembly having an upper slab of flexible polyurethane foam, the-lower surface of the slab having an openwork fabric embedded therein and a plurality of spring wire coils having one end disposed against the fabric and embedded in the foam of the slab penetrating the fabric.

A further object is to provide a method of embedding spring wire coils in a flexible slab of cellular reaction material involving the step of disposing a flexible openwork sheet between the reaction material and coils, the sheet acting as an insulation between the coils and the slab and leveling the reaction material during expansion while permitting a portion of the reaction material to penetrate the sheet and embrace the ends of the coils.

A still further object of the invention is to provide a spring wire coil assembly comprising a plurality of coils having opposite ends of the coils embedded in layers of polyurethane foam carried upon sheets of flexible material.

Another object is to provide a spring wire coil assembly comprising a plurality of coils having opposite ends of the coils attached to spaced sheets, at least one of which is flexible, the ends of the coils being bonded in position.

These and other objects and advantages residing in the present invention will more fully appear from a consideration of the following specification and the appended claims.

In the drawings,

FIG. l is a plan view of an assembly embodying the invention,

FIG. 2 is a front View of FIG. l,

FlG. 3 is a cross-sectional view taken on line llllll of FIG. l,

FIG. 4 is a fragmentary view taken on line lV-lV of FIG. 3 showing one embedded end of a coil,

FiG. 5 is a view similar to FlG. 4 taken on line V-V of FIG. 3 showing the other end of an embedded end of a coil, and

FIG. 6 is a fragmentary enlarged cross-sectional view taken on line VI-Vl of FlG. 1.

Referring to the drawings, the resilient seating or cushion assembly illustrating the invention comprises a slab 1t), spring coils 12, an insulator 14 between the coils 12 and slab 1t?, and a base or back 16.

The slab 1i) is preferably of flexible polyurethane foam in which a woven, open-mesh fabric of cotton, jute or other suitable strands constituting the insulator 14 is embedded along with one or more of the end convolutions 13 of the spring coils 12. ln practice, the foam forming the slab l@ is expanded through the open mesh of the insulator 14 and embraces the convolutions 18. Upon curing the foam, the insulator 14 and the end convolutions 13 ofthe coils 12 are bonded to the slab 1li.

The base or back 16 may be flexible, rigid or semirigid. If the 'oase lo is to be resiiiently supported upon a subbase of a seat cushion in an automobile, for example, in such event the base lo would be flexible. in FlG. 3, such a subbase is indicated by coil springs i9. A exi le base lo may be accomplished by using 1G o. woven burlap 28 and bonding the one or more of the end convolutions 22 of the coils 12 to the burlap 2o. Any suitable bonding material may be used for attaching the convoi* tions 22 to the burlap 2% such as latex and resin comenta. in practice, it has been found that coating the burlap 29 with a layer of uncured polyurethane foam, embedding the convolutions 22 in the foam and curing the assembly gives satisfactory results with the chemical reaction between the burlap and foam improving the structural characteristics ofthe vburlap 2li.

@ne method for fabricating the assembly of EGS. 1 and 2 is to ffst insert the spring coils l2 in a suitable fixture having a series of uniformly spaced pocltets into which the coils l?, may be inserted with a substantial rion of each coil spring extending out of each pocket. o help hold the coilc l2 in the pockets when the fixture s inverted, the woven open-mesh insulator 14 is laid over he exposed ends of the coils l2 and it may be marginally attached to the ixture. The nature, with the coils i2 held in the pockets by the insulator i4, may now be inverted and suspended in a suitable manner in the mold for the slab It@ with the insulator 14 being spaced from the bottom of the mold a distance equal to the central thickness o the slab it?.

With the insulator le and coils 12 disposed in the mold in 'the described above, the chemicals for producing the foam are placed in the mold. As the foam expands it will be leveled bythe insulator 14 with a portion of the foam passing through the interstices of the insulator i4 and embracing theV end convolntions'l of the coils l2. As' it' may be' desirable tof have a skirt 24 of foam about the l edges of the slab lil, the insulator la does not extend 'to the sides 'of the mold to permit foaming to talle place to aV greater extent around j d or semi-rigid base or back lo as, example, Where sheet metal or plywood is substituted the bui'lap Ztl, the base or back lo may function as n of the foaming operation in the mold and a i the fixture for the coils i2. With this arrangement the coils l2 would be bonded in the desiredrspaced relation upon the sheet metal or plywood, the insulator le would be laid over the free ends ot the coils 12 and attached to the marginal edges of the base or back lo and the assembly would be inserted into the mold in the saine manner as the iixture described above.

vWh re the bonding material for the convolutions 22 of the base or back 1o is polyurethane foam, the precureV of the same would talie place either before or after the molding of the slab l@ and the {inal cure or" both the slab l@ and the base or back 16 would be carried out as a single operation.

The preparation, formulation, molding and curing of polyurethane foam is well known in the art and forms no part of the present invention except in the sequence or steps claimed.

Having thus described our invention, what we claim is:

l. A spring coil assembly comprising a plurality of laterally spaced coils, a llexible foam slab, a loosely weveA fabric disposed between said slab and saidV coils, and a common bonding material for bonding said fabric and coils to said slab.

2. A spring coil assembly as defined in claim 1 wherein said bonding material is a homogeneous part of said slab.

3. ln combination with a supporting surface detined by separate spring elements, a spring coil assembly supported upon said spring elements, said assembly comprising a 'flexible closely woven buriap fabric directly disposed Woven fabric disposed upon the opposite ends of said coils` a flexible foam slab disposed on said loosely woven fabric,

a common bonding material for bonding said loosely woven fabric and said opposite ends of said coils to said slab.

References Cited in the le of this patent UNITED STATES PATENTS Germany 

1. A SPRING COIL ASSEMBLY COMPRISING A PLURALITY OF LATERALLY SPACED COILS, A FLEXIBLE FOAM SLAB, A LOOSLY WOVEN FABRIC DISPOSED BETWEEN SAID SLAB AND SAID COILS, AND A COMMON BONDING MATERIAL FOR BONDING SAID FABRIC AND COILS TO SAID SLABE. 